Automatic changeover mechanism



' AUTOMATIC CHANGEOVER MECHANISM Filed June 14, 1945 W 12 I V 5 1 11% A/5 B :30 (735/619 NvENTbRs Y l9 v A FRANK HUMBARGER a A KRALPHYCLPIERSONU .WILLISG. SCHEPMAN IATTORNEY,

nomical and practical means of insuringa con-' Patented Aug. 15, 19502,518,94

UNITED stares rnrsm orncs 2,518,894 ,evf oMei-" g-ci em vm MECHANISMFrank F. Humbarger, United States Navy, Ralph C. Pierson, Indianapolis,and Willis G. Schepman, Speedway, Ind., assignors to Union Carbide andCarbon Corporation, a corporation of New York Application June 14, 1945,Serial No. 599,486

- 10 Claims. '(01. 137-144) maintaining one of two regulator springs inaless-compressed state (reserve side). The ends 1 This invention relatesto an automatic servicereserve changeover mechanismwhich is adapted tomaintain an uninterrupted supply of fuel gas of the interlocking bar aretapered and the disto the consumer by automatically changing the tancebetween them is longer than the face-tosource of gas from service toreserve when the .--;;'face distance between two push rods, so that theservice gas supply has been withdrawn. bar is forced by the otherregulator spring into Originally, liquefied petroleum gas systems, agroove in the push rod being depressed to load for example, were allnon-automatic, and when its spring; thus relieving sprin pressure onsuch the service gas supply cylinder was emptied it other push rod, andthereby causing the lat was necessary for the customer to gooutdoorswaiter to be released from its depressed position. and turn on thereserve supply of gas. Since Referring to the drawing: the customer hadto be educated to the opera- Fig. 1 is a fragmentary view in frontelevation tion of the cabinet and had to depend 'upon himof adistribution system exemplifying the invenself for the control of thegassupply, the need tion; and for an automatic changeover mechanism became154! Fig. 2 is an enlarged View in section taken on imperative, Thisneed increased with the advent line 2-2 of Fig. 1, showing details ofconstruction of the use of'liquefiedp'etroleum gas forrefrigei of thechangeover mechanism. ation, automatic water heating, etc; The auto- Thesystem shown in Fig. 1 comprises a pair matic changeover mechanismwasdesirable since of gas containers such as cylinders 3, one of itovercame the disadvantages associated with "which constitutes a servicesource of gas supmanually changing the supply byproviding uhply and theother, a reserve source of gas supply. interrupted service. Thecylinders 3 have their cylinder valves 4 con- The main object of thisinvention is to provide nected by pipes or leads 5 to a changeovermechaan improved service-reserve changeover mechanism'M which isdescribed below in detail. A nism that is fully automatic, providingeco- 25 signal gauge S is connected to the device M by a pipe 6. Alsoconnected to the manifold is a stant or uninterrupted supply of'gas ina; dualservice regulator R the gas outlet of which is consourceliquefied petroleum gas distribution sysnected to an appliance such as astove, by a tem. Another object is to provide a fluid districonduit 1.19 1 ys m Changeover mechanism that is 0 The changeover mechanism M, asillustrated safe, efficient, compact, simple and effective. in Fig. 2,comprises two gas inlet passages A, two According to the invention,"there is provided gas pressure chambers B, a gas outlet C, a signal anautomatic changeover mechanism for liquegauge outlet (not shown), a,lower valve body E, fied petroleum' gas distribution systems, which anupper valve body F, and two spring chambers comprises two supplyregulator valves, one for" 5 '-I-G. Since both sides of the device M aresimilar, e serv ce as Sou ce andtheother for the i' for brevity andclearness, only one side will be serve gas source, operativeautomatically to described below. maintain an uninterrupted supplyfoigas when The gas inlet passage A is internally threaded. the pressure ofthe service gas source falls to'a at I!) and is provided with a nozzle Nhaving an predetermined value.- When'thegas' in the sew: 0 enlarged gasinlet passageway portion l2 and a ice source falls to such value, thechangeover reduced portion l3. The gas inlet passage A is mechanismautomatically changes the system formed in an integral portion of thelower valve over to the reservegas source. The changeover body E in anysuitable manner, such as, casting, mechanism does not p al 11111161 l yd machining, or a combination of such operations, pressure. That is tosayj the' supply regulator 5 whereas the nozzle N is an insertof the gasinlet valves operate to reduce 'the' ga's pressure to" passage A. whichthe regulators are "subjected" by" closing The gas pressure chamber B isbounded by the the valves automatically'in response to certain gas inletnozzle N in the gas inlet passage A on gas pressures whicharelowcompared to 7 full the gas inlet side, It is bounded below by thecylinder pressure; Further, according to the 50 'lower valve body E,which is also a portion of invention, anovel service-reserve alternatingthe side of this chamber B. Above, it is bounded ec a ism is provid d ai "a interlockin by a flexible diaphragm 14. On the gas outlet bar thatonly allows one gas source to be connected in reserve at a given time.leads to the gas outlet C and signal gauge outlet Such mechanismprovides positive means for lis -(not shown) The gas pressure chamber Bconsideit is bounded by a gas passageway l5 which 7 tains a valve seatis, composed of suitable resilient material, which is capable of makingcontact with the gas inlet nozzle N and is part of a pivoted valve seatholder IT.

For the diaphragm and valve seat, any comparatively resilient materialmay be-used that is not soluble in liquefied petroleum gas, such aspropane, for example, in either the liquid or vapor states, and also isrelatively unaffected b tem-- perature.

The valve seat holder I1 is actuated by'a lower diaphragm plate is abouta fulcrumpivot- IS. A lever arm 26 is rigidly connected: to the valveseat holder [1. The lever arm 29 extends through and is freely movablerelatively to-aperture" 2t that is formed in a portion of the lowerdiaphragm plate [8. The aperture 2! is conicall counterbored at itsopposite ends to leave an intermediate aperture portion slightly largerin cross-- section than the lever arm 28, and to provide a knife edgethat engages the lever arm 2-92 The: arm 26 is movable through the.lever opening 2-! when the lower diaphragm plate I8 is acted upon. bythe flexible diaphragm M. The valve seat holder I! is pivotallyattached'to an elevated portion 23 of the lower valve body E.This-arrangement minimizes humming, which greatly lessens. the life of:the valve, and also produces a more constant flow of gas.

A diaphragm screw 26" holds the lower diaphragm plate I8 in the center.of the: upper wall of the gas. pressure chamber. B and in contact withthe flexible diaphragm: l4; opposite. an upper diaphragm and lowerspring plate 25, forming; a gas-tight seal.

The flexible diaphragm member. is secured il'il gas-tight relationbetween flat rim portions 26- and 21 of the lower valve body E and uppervalve body F, respectively, by screws 28. The flexible diaphragm member.thus-acts as a gasketbetween the valvebodiesE and F.

Gas outlet passage [5 connects the gas pressure chamber B to the gasoutlet (3 and: signal: gauge outlet passage. The gas outlet 0' is at oneend of the connecting passage and the signal gauge outlet at the. other.The gas outlet C'is-connected to the regulator R by acoupling 8;, andthe signal gauge outlet is connected to the signalgauge S by the pipe 6.

The spring chamber G is bounded on. the sides by the upper'valve body1?, on the: bottom by the flexible diaphragm M, and on the top by a pushrod 29. The spring chamber G contains at least three ribs 38 which are aportion of the upper valve body F and serve as guides for a va-lvespring3 I. The valve spring 3| presses against the'plate- 25 at its lower end;whereas the upper end of the spring is in contact with" an uppervaive'plate 32 which thereby is heldagainst a pressure adjusting screw33. An elastic lock-nut 34 or other suitable means retains the pressureadjusting screw 33 in its adjusted position, and is incor porated in thehollow push rod 29. The screw 33 is mounted on the inside of thepushrod. for adjustment to determine the upper operating pressure on thediaphragm I4 when the spring 3.! is compressed.

A ring 35 is threaded inside of the body F, pr0- viding a stop whichengages an annular shoulder 44 on the rod 29 and thus limits the outwardmovement of rod 29 by the spring 3 i, so that adjustment of the screw33. determines the lower operating pressure of the spring when the rod29 is released. The ring 35 also acts as part of the guide for the pushrod 29.

A push but on 3 i I attached to the push rod 29 by suitable means suchas a locking pin 31. The push button 33 closes the upper end of the rod,so that the screw 33 is not readily accesible. An interlocking bar 38having rounded ends is disposed in an interlocking bar cavity or way39in the body F. The bar 38 is slightly greater in length than thefaceto-face distance between push rods 29, so that one end is located ina groove 40 of the compressed push rod when the other end is in contactwith the surface outside of the groove in the other push bar. Av cap llis provided for an opening through which the interlocking bar 38 ismoved when the. parts of changeover mechanism M are'being assembled.

Small air vents or holes 43 are provided in the wallv of the upper valvebody F,-so as to maintain atmospheric pressure on the upper side of thediaphragm Hi.

The illustrated changeover mechanism M thus consists of two"interconnected gas supply regulators'K, one for the service gas sourceand the other for the reserve gas source. Either regulator may be madethe service side by depressin a push button 36; which automaticallymakes the other one the reserve side. The interlocking bar 38 is shiftedby the force of the other spring 3|, acting through its push rod 29 andgroove 59 on the rounded end of the bar, and thus latches the selectedsupplyregulator in adjusted position, when the groove 40 of the selectedrod is presented to the other end; of the bar 38. Because of thecompressionof thespring-3-E, the gas supply regulator; which operatesata lower gas pressure, automatically meets the demand for gas from theservice cylinder; The signal gauge S which works on thepressureidifierential between the service and: reserve sources,indicates when the service gas supply container has been depleted.

When the-service gas supply container has become depleted, the other gassuppl regulator automatically meets the demand for gas from the reservecylinder. The automatic changeover mechanism occurs by virtue of thefluid pressure in conjunction with the different compression loads onthe springs 31-. The more compressed spring 3| causes the regulatorvalve controlled by such spring to operate first, and when the gaspressure falls sumciently, the less compressed spring 3! automaticallycauses its valve to operate. When the gas pressure in either chamber Breaches the value at which the springs 3| are set, the correspondingvalve is automatically closed, so that the supply of gas is pres sureregulated first by one supply regulator (service) then by the othersupply regulator (reserve). When the reserve; regulator valve remainsclosed, the-service regulator operates; and when the reserve regulatoris in operation, the service regulator valve remains open.

The signal gauge S may be merely a pressure gauge whose face has beenblanked oh and a red portion is put on the gauge dial which is set to'show redwhen the automatic changeover mechanism is operating on thereserve cylinder. Thus, the consumer notifies a service man that he isnow using the reserve cylinder. When the service man replaces the emptycylinder, he reverses the positions of the push buttons 36 by simplydepressingthe reserve push button and thereby the former service sidebecomes the new reserve side.

Since the device lVL may be used with a conventional signal. gauge S,the gas supply regul'atorsKarefsetat approximately 16 p. 55 i. andapproximately 9 p. s. i., for service'and reserve operation,respectively. If other operating conditions are to beimet pressureregulation'can be made.

The changeover mechanism M has sufiicient capacity, when coupled with aservice 'regulator R, that reduces the pressure to approximately teninches ofwater column pressure and isused in almost all. propanedistribution systems, to provide fifty cubic feet per hour, or enoughcapacity to provide a three-cabinet installation (two cylinders each)per automatic changeover mechanism M and service regulator R. It will beevident that details of the disclosed constructioii may be varied, andcertain features may be utilized independently of others, withoutdeparting from the principles of the invention.

While the invention has been described in connection witha gas, it willbe understood ,thatthe invention is not limited thereto, but may ,beusedin connection with aliquid, and the term"fluid in the claims is intendedto include liquid as well as gas.

We claim:

1. An automatic service-reserve changeover mechanism for dual-sourcefluid supply systems, comprising a pair of fluid supply regulatorsincluding differently loaded springs, and means for alternating theloads on said springs comprising push rods, each provided with exposedmanually engageable means in line with the major axis of thecorresponding spring and latch means acting by virtue of the force ofone of said springs automatically to release one push rod and latch theother push rod when the latter is pushed to load its spring.

2. An automatic service-reserve changeover mechanism for dual-sourcefluid supply systems, comprising a pair of fluid pressure responsiveregulators adapted to operate at difierent fluid pressures, so that oneregulator operates until the service fluid source is depleted, whereuponthe other regulator is caused to operate, each of said regulatorscomprising a regulator spring, a push rod opposing the force of saidspring, and a push button on said push rod, and a common latch for saidpush rods, the arrangement being such that a selected regulator isloaded by pushing the push button to move the push rod longitudinallydirectly against the force of the spring until said latch operatesautomatically by virtue of the force of the other spring to secure thepush rod in loaded position.

3. In combination, a pair of compression springs, spaced parallelmanually engageable push rods for selectively adjusting the force ofsaid springs, said rods having grooves, and a cross bar having endsdisposed between said rods, the length of said bar being such that oneend fits the groove of one rod when the other end contacts the surfaceoutside of the groove of the other rod, said grooves being positioned sothat pushing one push rod directly against the force of its spring movesthe groove of that rod into line with said bar, causing the other springto force its push rod to shift said bar out of the groove of the latterpush rod, and into the groove of the pushed push rod, thereby releasingthe former and latching the latter, the arrangement being such that onepush rod is released and the other is latched by merely pushing the rodselected to be latched.

4. An automatic service-reserve changeover mechanism comprising a pairof gas supply regulators each'including a gas inletnozzle, a valvelever, a valve seat on said lever facing said nozzle,a valve lever,"avalveseat on said leverfacing said nozzle and providing a gas supplyvalve,

' .5 a gas pressure responsive diaphragm connected to said valve lever,means including said diaphragm providing a gas pressure'chamber foreach" regulatonsu'ch chambers having a common gas outlet, a compressionspring acting on the ,iside of" said diaphragm opposite each chambertowclosesaid valve, and a push' rod compressing said spring, andcommo'nlatch means acting by virtue of'the 'force'of one of said springsautomatically torelease" one push rod and latch the other push rod whenthe latter is pushed' to load its spring.

'5.- An automatic service-reserve changeover mechanism comprising onebody having two gas inlet-passages, two gas chambers, and a coing mongas outlet, a diaphragm member disposed on said body, a secondbodyhaving two spring chambers and a common way, said second body beingdisposed on said'diaphragm member with.

said spring chambers opposite said gas chambers, means securing saidbodies together with the diaphragm member clamped therebetween,compression springs in said spring chambers acting against the resultingdiaphragms, valves in said gas chambers operatively connected to saiddiaphragms, push rods compressing said springs, said rods each having anexposed push-end and a lateral recess, and a reciprocatory cross bar insaid common way, one end of said cross bar engaging a recess and therebylatching one of said push rods in spring loaded position by virtue ofthe contact of the other end of said bar with the periphery of the otherrod.

6. In a service-reserve changeover mechanism, a gas supply regulatorcomprising a regulator spring, a spring push rod which is tubular, apush-button removably mounted on the outside of said rod, retainingmeans mounted on the inside of said rod, a screw threaded in saidretaining means, said screw being accessible through said tubular rodwhen the push-button is removed, and a spring engaging member disposedbetween said spring and said screw, so that the force of said spring maybe adjusted by adjusting said screw in said retaining means.

7. In a service-reserve changeover mechanism, a gas supply regulatorcomprising a body having a spring chamber, said body having a hole inline with said chamber, a hollow push rod in said hole, said rod havinga shoulder, an adjustable annular stop for said shoulder, threaded tosaid body within said hole for limiting the outward movement of said rodunder the force of said spring, and a push-button having a stem securedwithin said hollow push rod, said pushbutton being adapted to engagesaid body for limiting the inward movement of said rod.

8. In a fluid pressure regulator, in combination, a casing having achamber provided with a fluid inlet; means, including a diaphragmresponsive to the fluid pressure within said chamber, for controllingthe admission of fluid through said inlet; and adjustable means forapplying force against the outer side of said diaphragm, said adjustablemeans including a spring bearing against said diaphragm, an adjustableabutment mounted on said casing and having a bore extendingtherethrough, a push rod in said bore, said push rod having a shoulderadapted to engage said abutment, said push rod also having an axialbore, a screw bearing against said spring and adjustably mounted in oneend of said bore;

and a; push button: closing theopposite. end. of: said bore..

9; In an automatic-changeover mechanism,-.the: sub-combinationcomprising a: body having spaced parallel push-rod bores, and a common.cross-- bar way extending between suclr bores; 9;; push;

rod disposed in each, bore for limited: longitudiz nalmovement betweenin and out. positions;. and a cross-bar disposed in. such. way forlimited' longitudinal. movement between; said rods,. the ends of said'bar and the lateral surfaces-of said rodshaving cooperating shapesadapted tol cause the bar to positively locklone pushsrod; in: inposition when the other-push rod: is in out position, and: permit thelatter. push rod" to. be" moved to in position to alternate thelock;said.

cross-bar being completely housed within the body.

10; In-a service-reserve changeovermechanisrrr; a fluid" pressureregulator comprising a regulator spring, a push-rod, a body having achamiher for said spring, a stop for: said push-rode ad'- justablymounted on saidbody, adjustable: meansincluding axscrew disposedbetween-saidpushsrodi and, said spring, and means for-latching said rodto, hold the rod in place after. said spring has:

been compressed, the'adjustment of said-stop-and I screw determining theminimum spring-compres- REFERENCES CITED The following references are ofrecord in the.

file of this patent:

UNITED STATES PATENTS Number Name Date 986,921 Jackson Man. 14, 1911.2,168,701 Buttner Aug. 8, 1939,v

